Process of dyeing fibrous materials



Patented Sept. 18, 1928.

UNITED STATES PATENT OFFICE.-

J'OSEPH N'U'SSLEIN, OF LUDWIGSHAIEN-ON-THE-BHINE, GERMANY, ASSIGNOR TO I. G. FABIBENINDUSTRIE AKTIENGESELLSCHAFT, OI FRANKFORT-ON-THE-MAIN, GER- .MAINY, A CORPORATION 01! GERMANY.

' PROCESS OF DYEING FIBBOUS MATERIALS.

No Drawing. Application filed November 23, 1926, Serial No. 150,884, and in Germany December 7, 1925.

In the known processes for producing dyeings on fibrous materials by the oxidation of aromatic amines, such as aniline and 1ts homologues, the amines are employed in the form of water-soluble salts, in most cases those of mineral acids such as hydrochloric acid. In order to reduce the risk of damage being done to the fibres by the employment of salts of such strong acids, it has been proposed to employ tartrates or basic salts of the aromatic amines," but the operation according to these methods affords considerable difliculties.

I have now found that instead of the aforementioned water-soluble salts the free amines can be employed provided they are finelydispersed 0r dissolved in water with the aid of suitable means. By this method dyeings can be produced without exposing the fibres of fibrous materials to the risk of damage, while dyeings are obtained as fast as those prepared with the aid of watersoluble salts.

According to my present invention, the amines are dispersed or dissolved in water with the aid of a water-soluble emulsifying agent. A great variety of such agents may be used. As examples of such agents, which are of particular value, aromatic sulfonic acids which preferably should be substituted by side chains, or salts of such acids, or soaps, Turkey red oil, or organic solvents whether alone or in conjunction with the aforementioned substances, may be mentioned. In all cases protective colloids may also be present. When salts of aromatic sulfonic acids substituted by al 1, aralkyl, or aiyl .oups or hydroaromatic radicals, which sulfonic acids may also contain other substituents, are employed in a suitable quantity which can easily be ascertained by some tests, the aromatic amines are not only converted into finely dispersed aqueous emulsions, but into clear solutions.

My invention is applicable in the production of fast dyeings on fibres or fibrous materials, whether of animal, vegetable or artificial origin. The oxidation of the aromatic amine may be carried out in the bath containing the amine or in a. subsequent operation. The fibres or fibrous materials may be impregnated with the amines either once or several times. The process is applicable Example.

1 kilogram of aniline is dissolved in 5 litres of a 20 per cent aqueous solution of diisopropyl naphthalene sulfonic acid sodium salt or N -dibutyl-aniline sulfonic acid sodium salt. The clear solution so obtained which, if desired, may be diluted with water, is at once ready for use. Yarn is impregnated therewith and then subjected to an oxidizin treatment. Or the solution may be added to a solution of potassium bichromate and sulfuric acid, whereupon yarn is introduced into the mixture and oxidation effected therein. Or the aniline solution is mixed with a thickening and an oxidizing agent and, if desired, with a catalyst promoting the oxidation, and the product thus obtained is employed for printing.

I claim:

1. The process of producing dyeings on fibrous materials which consists in applying to the fibre a mixture comprising an aromatic amine, practically insoluble in water, water and a water-soluble emulsifying agent, and oxidizing the amine.

2. The process of .roducing dyeings on fibrous materials whic consists in applying to the fibre a mixture comprising an aromatic amine, practically insoluble in water, water and a salt of an aromatic sulfonic acid sub- Stituted by a side chain, and oxidizing the amine.

3. A composition of matter comprising an aromatic amino, practically insoluble in water, a water-soluble emulsifying agent and an oxidizing agent.

4. A composition of matter comprising an aromatic amine, practical] insoluble in water, a salt of an aromatic sulfonic acid substituted by a. side chain and an oxidizing agent.

In testimony whereof I have hereunto set my hand.

JOSEPH NUssLEIN. 

